This glossary, version 2.0, is a second and revised version of the glossary version 1.0 dating of March 23rd, 1998. It accumulates the term definitions which are displayed in the NetAcademy's online glossary query. Each year we sum up such an archive version of academic definitions emerging from the NetAcademy, thus documenting the knowledge generating process of defining and improving definitions. (www.netacademy.org)